This invention relates to polytrimethylene ether esters, and their manufacture and use.
Polytrimethylene ether glycol (xe2x80x9cPO3Gxe2x80x9d) and its use in thermoplastic elastomers, as well as in other applications, have been described in a number of patents and patent applications. PO3G can be prepared by dehydration of 1,3-propanediol or by ring opening polymerization of oxetane. PO3G can also be prepared from 1,3-propanediol, preferably as described in U.S. patent application Ser. Nos. 2002/7043 A1 and 2002/10374 A1, both of which are incorporated herein by reference.
Polyether ester elastomer comprising polytrimethylene ether ester soft segment and tetramethylene and trimethylene ester hard segments are described in U.S. patent application Ser. Nos. 10/016,195 and 10/016,023 (Attorney Docket Nos. CH-2767 and CH-2858) both of which are incorporated herein by reference. Polytrimethylene ether ester amides are described in U.S. patent application Ser. No. 10/073,745, filed Feb. 11, 2002 (Attorney Docket No. CH-2816 CIP), which is incorporated herein by reference. Polyurethanes and polyurethane ureas are described in U.S. patent application Ser. No. 10/215,575, filed Aug. 9, 2002 (Attorney Docket Nos. CH-2833), which is incorporated herein by reference.
While not wishing to be bound by theory, it is believed that, due to the incompatibility of the hard and the soft segments, phase separation occurs. The two phases constitute the elastomeric matrix. The hard segments form microdomains of crystallites, while the soft segments and a fraction of the crystallizable hard component that has not reached crystalline order form the amorphous phase. It is known to those skilled in the art that the better the distinction between the crystalline microdomain and the amorphous phases the better the elastic properties. Phase separation and microdomain formation in block polymers directly influence thermal behavior, dynamic mechanical properties, mechanical and rheological properties, and permeability and transport phenomena of the elastomeric system. It is taught that the morphology of the elastomeric system, and its properties, depend heavily on the crystallization conditions of both the hard and soft segments. The block that crystallizes first has a tendency to xe2x80x9cfreezexe2x80x9d the entire structure, and in this way, to impose the crystallization of the other block. Thus, in order to form a clear two phase morphology, the more amorphous in nature of the soft segment, the better, as it will take longer and more difficult to crystallize (either by itself or induced by the hard segment residues in the soft segment phase).
In U.S. patent application Ser. Nos. 10/016,195 and 10/016,023 (Attorney Docket Nos. CH-2767 and CH-2858), it was taught that a slower crystallizing polytrimethylene ether glycol soft segment in the block polymer elastomer provides better elastic properties (e.g., unloaded power, stress decay, % set) as compared to that of polytetramethylene ether glycol soft segment. Thus the soft segment needs to be as amorphous as possible, as measured by the crystallization rate. While polytrimethylene ether glycol itself provides an excellent soft segment, even more amorphous and more slowly crystallizing soft segments are desirable. More amorphous soft segments would lead to a better two-phase morphology and give further improvements in the final thermoplastic elastomers.
There is a continuing need to improve polytrimethylene ether glycol and thermoplastic elastomers made therefrom. The present invention provides a novel random polytrimethylene ether ester and novel thermoplastic elastomers with advantageous properties.
The invention is directed to a random polytrimethylene ether ester prepared by polycondensation of 1,3-propanediol reactant and about 10 to about 0.1 mole % of aliphatic or aromatic diacid or diester.
It is also directed to a random polytrimethylene ether ester by polycondensation of about 90 to about 99.9 mole % of 1,3-propanediol reactant, calculated based on the amount of 1,3-propanediol and 1,3-propanediol units, and about 10 to about 0.1 mole % of aliphatic or aromatic diacid or diester.
In another embodiment, it is directed to a random polytrimethylene ether ester by polycondensation of about 80 to about 99.1 mole % of 1,3-propanediol reactant, calculated based on the amount of 1,3-propanediol and 1,3-propanediol units, about 10 to about 0.1 mole % of aliphatic or aromatic diacid or diester, and up to about 10 mole % of diol reactant other than 1,3-propanediol reactant, calculated based on the amount of diol and diol units.
In a further embodiment, it is directed to a random polytrimethylene ether ester by polycondensation of 1,3-propanediol reactant and about 10 to about 0.1 mole % of aliphatic or aromatic diacid.
The random polytrimethylene ether ester is preferably prepared from about 90 to about 99.9 mole % of the 1,3-propanediol reactant and the about 10 to about 0.1 mole % of aliphatic or aromatic diacid. In another embodiment, it is preferably prepared from about 80 to about 99.9 mole % of the 1,3-propanediol reactant, the about 10 to about 0.1 mole % of aliphatic or aromatic diacid, and up to about 10 mole % of diol reactant other than 1,3-propanediol reactant.
Preferably the 1,3-propanediol reactant is selected from the group consisting of 1,3-propanediol, and oligomers and prepolymers of 1,3-propanediol having a degree of polymerization of 2 to 9, and mixtures thereof.
In one preferred embodiment, the random polytrimethylene ether ester of claim 1 wherein the 1,3-propanediol reactant is 1,3-propanediol. In another preferred embodiment, the 1,3-propanediol reactant is selected from the group consisting of prepolymers of 1,3-propanediol having a degree of polymerization of 2 to 9 and mixtures thereof.
Preferably the aliphatic or aromatic diacid or ester is selected from the group consisting of aromatic dicarboxylic acids and esters, and combinations thereof.
Preferred is the aliphatic or aromatic diacid, and preferably the diacid is selected from the group consisting of aromatic dicarboxylic acids and combinations thereof. Preferably the aliphatic or aromatic diacid is an aromatic diacid selected from the group consisting of terephthalic acid, isophthalic acid, bibenzoic acid, naphthalic acid, bis(p-carboxyphenyl)methane, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 4,4xe2x80x2-sulfonyl dibenzoic acid, p-(hydroxyethoxy)benzoic acid, and combinations thereof.
Preferably the aliphatic or aromatic diacid or diester is selected from the group consisting of terephthalic, bibenzoic, isophthalic and naphthalic acid; dimethyl terephthalate, bibenzoate, isophthlate, naphthalate and phthalate; and combinations thereof.
Preferably the aromatic diacid is selected from the group consisting of terephthalic acid and isophthalic acid. Most preferred it is terephthalic acid.
Preferably the random polytrimethylene ether ester is prepared from about 95 to 99.5 mole %, more preferably about 97.5 to 99 mole %, of the 1,3-propanediol reactant and about 5 to about 0.5 mole %, more preferably about 2.5 to about 1 mole %, of the aliphatic or aromatic diacid.
In another embodiment, the random polytrimethylene ether ester is preferably prepared from about 85 to about 99.5 mole %, more preferably about 87.5 to about 99 mole %, of the 1,3-propanediol reactant, about 5 to about 0.5 mole %, more preferably about 2.5 to about 1 mole %, of aliphatic or aromatic diacid or diester, and up to about 10 mole % of diol other than 1,3-propanediol reactant.
In one preferred embodiment, the random polytrimethylene ether ester is prepared by a process comprising the steps of: (a) providing (1) 1,3-propanediol reactant, (2) aliphatic or aromatic acid or ester; and (3) polycondensation catalyst; and (b) polycondensing the 1,3-propanediol reactant to form a random polytrimethylene ether ester, preferably at less than one atmosphere pressure.
In another preferred embodiment, the random polytrimethylene ether ester is prepared by a process continuous process comprising: (a) continuously providing (i) 1,3-propanediol reactant, (ii) aliphatic or aromatic acid or ester and (iii) polycondensation catalyst; and (b) continuously polycondensing the (i) 1,3-propanediol reactant and (ii) aliphatic or aromatic acid or ester to form random polytrimethylene ether ester.
The invention is also directed to thermoplastic elastomers prepared from the random polytrimethylene ether ester as a soft segment and a hard segment polymer selected from the group consisting of polyesters, polyamides, polyurethane, and polyurethane urea. One preferred embodiment is directed to a polyether ester elastomer comprising a soft segment from the random polytrimethylene ether ester and alkylene ester hard segment, preferably a C2 to C12 alkylene ester hard segment, preferably tetramethylene ester hard segment or trimethylene ester hard segment. Another preferred embodiment is directed to a polytrimethylene ether ester amide comprising a soft segment from the random polytrimethylene ether ester of claim 1 and a polyamide hard segment. Yet a further preferred embodiment is directed to a polyurethane or polyurethane urea elastomer prepared from (a) the random polytrimethylene ether ester, (b) diisocyanate and (c) diol or diamine chain extender.
The introduction of the minor amount terephthalic acid provides advantages, including: (a) decreasing the time for the reaction to produce desired molecular weight; and (b) providing a means to further decrease the crystallization rate and thereby providing a more amorphous character in the soft segments in the thermoplastic elastomers made with the polytrimethylene ether ester, as compared with those made with polytrimethylene ether glycol. Other advantages are described below.